Much of the confusion with caps stems from the fact that they are made of a different plastic resin than the bottle or jug they secure. Most caps are made of polypropylene (#5 plastic), with some (like sports drink bottles) composed of high-density polyethylene (#2 plastic). Plastic bottles and jugs are typically #1 or #2 plastic.

Plastic Cap & Lid Recycling Preparation

For plastic bottles, you need to ask your local recycling program whether caps are accepted before trying to recycle them with the bottle. Some will ask you to leave them on, some accept caps but want them separated, and some will ask you to throw them away.

For plastic containers (e.g. butter tubs, yogurt cartons), the lid is usually made of the same material as the base. If the container is #5 plastic, odds are strong that the lid is as well. In these cases, feel free to reattach the lid before recycling if your program accepts non-bottle plastics.

If your local recycling program doesn’t accept caps and you know they are made of polypropylene, consider the Preserve Gimme 5 program, where you can recycle all #5 plastics by mail.

Why Recycle Plastic Caps & Lids

A 2016 debris removal effort of Midway Atoll, an island with a population of less than 60 in the middle of the Pacific Ocean (1,300 miles from Honolulu, the closest city), found almost 5,000 bottle caps; if not recycled, these caps travel a large distance and pose a danger to marine life because of their small size

Plastic caps don’t biodegrade, meaning it will take hundreds of years for them to decompose in a landfill

Plastic Cap & Lid Recycling Process

Assuming you left the cap on the bottle, the first step in the recycling process is to separate the bottles and caps into their individual resins. The material recovery facility (MRF) will use a pressurized system to expel caps and flatten bottles. Plastics are then soaked in water, where the bottle (made of #1 plastic) will sink and the cap (#2 or #5 plastic) will float.

Recyclers will shred the #2 or #5 plastic into flakes, which are washed, rinsed and dried. Flakes are then melted into pellets, which are transported to a manufacturer to make new plastic caps or other materials, such as casing for car batteries, storage containers or reusable plastic bags.

Frequent Plastic Cap & Lid Recycling Questions

While most curbside recycling programs are adopting the Caps On standard, your local program may be different. You’ll want to verify acceptance and preparation rules before recycling your caps at the curb.

There are several reasons why caps are not as commonly accepted as plastic bottles. Some programs want to ensure that no liquid remains in the bottle, and the only way to do this is to remove caps. There are potential safety concerns that arise when a plastic bottle is crushed with the cap on and the cap goes flying. Caps are also usually made of a plastic resin (polypropylene, or #5) that has a lower recycling commodity market than the bottles.

If you know your local program doesn’t accept caps, you should try to contain them in a plastic bag before putting them in your garbage bin. That way, they are less likely to end up as marine debris. If you’re at the beach and there are no recycling or trash bins around, take the bottles home with you instead of leaving them as litter.

No. The closest you will find is that several states have passed laws requiring plastic bottles be recycled, including California, Massachusetts, New Jersey, North Carolina and Pennsylvania, but they mention nothing about caps or lids.

Polypropylene is one of the most common plastic resins today, used in everything from car batteries to laundry baskets. These large products are ideal for using recycled content, where they can last for years instead of in a bottle cap designed for one use. As a result, most recycled polypropylene is used to make non-food packaging.

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